1. Technical Field
The present invention relates to a printed circuit board and a method of manufacturing the same, and more particularly, to a printed circuit board including a electromagnetic wave shielding structure and a method of manufacturing the same.
2. Description of the Related Art
A printed circuit board (PCB), which forms and prints line patterns on an electrical insulating board using a conductive material such as copper, indicates a board immediately before an electronic component is mounted thereon. That is, the PCB indicates a circuit board on which a mounted position of each electronic component is secured and a circuit wiring connecting electronic components to each other is printed on a flat plate surface and is fixed in order to densely mount many various kinds of electronic components on the flat plate.
Recently, in accordance with the development of an electronic industry, the use of a package in which memory chips are mounted on many electronic devices has rapidly increased. Therefore, in accordance with miniaturization, lightness, and multi-functionalization of an electronic product, thinness of an electronic product packaged has been required. As a result, the thinness or an increase in density of the printed circuit board which is one of important components has also been demanded.
Meanwhile, while a trend of slimness and lightness of a portable mobile and the electronic device for display has rapidly progressed, a transfer speed of signal between components in the device is speeded up, and the circuit board becomes a micro-circuit having high density, damage of electromagnetic interference (EMI) according to an electromagnetic wave noise occurring between circuits adjacent to each other has become increased.
In order to effectively shield the electromagnetic wave as described above, it is required to enclose the printed circuit board by a conductor film having excellent electrical conductivity to allow the electromagnetic wave occurring in the printed circuit board to be decreased through the conductor.
Therefore, the electromagnetic wave is shielded by attaching a metal thin film such aluminum foil or silver foil having excellent conductivity to the circuit board or uniformly applying a conductive paste which is manufactured by dispersing a conductive powder into a binder resin on the surface of the circuit board. Alternatively, a conductive adhesive sheet type product, or the like, in which the conductive paste is made in a sheet form and heated and attached may be applied.
In this connection, Korea Patent Laid-Open Publication No. 10-2001-0006198 suggests a board including a transmission line, a shield unit of shielding the transmission line which is arranged so as to enclose around the transmission line, and an insulating layer arranged between the transmission line and the shield unit.
However, the shield unit having the above-mentioned structure cannot but occupy one layer in an inner space of the board. Therefore, the number of layers of the board increases, such that the demand for the thinness of the board and the increase in density of the board is not met.